Functional Roles of Arbuscular Mycorrhizal Fungi and Plant Growth-Promoting Rhizobacteria in Pistachio: Implications for Stress Tolerance, Nutrient Acquisition and Disease Suppression
This review critically examines the current knowledge on the functional roles of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria in pistachio production and identified the key knowledge gaps and research priorities required to improve the consistency, scalability, and field validation of microbiome-based approaches for sustainable pistachio production under increasingly challenging environmental conditions.
Abstract
Pistachio (Pistacia vera L.) is among the most economically important nut crops worldwide. They are increasingly exposed to the environmental constraints associated with climate change, including drought, salinity, nutritional imbalances, and heightened disease pressure. These stressors compromise plant growth, physiological performance, nutrient acquisition, and orchard productivity, highlighting the need for sustainable strategies to enhance crop resilience. This review critically examines the current knowledge on the functional roles of arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) in pistachio production. Evidence indicates that AMF and PGPR contribute to plant performance through multiple complementary mechanisms, including improved nutrient mobilization and uptake, maintenance of ionic homeostasis, enhancement of water-use efficiency, stimulation of antioxidant defenses, modulation of stress-related signaling pathways, and suppression of phytopathogens. AMF primarily enhance phosphorus acquisition, water relations, and soil structural stability, whereas PGPR contribute to nutrient solubilization, biological control, and induction of plant defense responses. Despite promising experimental results, most studies have been conducted under controlled conditions, limiting the translation of microbial inoculation strategies to commercial orchards in the field. We identified the key knowledge gaps and research priorities required to improve the consistency, scalability, and field validation of microbiome-based approaches for sustainable pistachio production under increasingly challenging environmental conditions.
Oil palm (Elaeis guineensis Jacq.) is a strategically important plantation commodity whose productivity is significantly influenced by environmental conditions. Abiotic stresses, particularly drought, impede plant growth and substantially reduce yield. As the impacts of climate change intensify and pressure on land resources increases, sustainable approaches to enhance plant resilience are increasingly needed. Among these, this study employs a systematic literature review and comparative analysis of globally published scientific literature (2021–2026) to examine the physiological, biochemical, and molecular mechanisms of beneficial microorganisms. Specifically, it synthesizes findings on how endophytes and arbuscular mycorrhizal fungi (AMF) improve plant water and nutrient status, mitigate oxidative stress, and enhance growth and stress tolerance in oil palm (Elaeis guineensis Jacq.) the utilization of beneficial microorganisms such as endophytes and arbuscular mycorrhizal fungi (AMF) has emerged as a promising strategy. This review aims to summarize and analyze the roles of endophytes and mycorrhizae in improving the tolerance of oil palm to various abiotic stresses, based on globally published scientific literature. The synergistic interaction between endophytes and AMF has been shown to positively affect plant nutrient and water status, reduce oxidative stress, and improve growth from the seedling to the mature plant stage under stress conditions. Despite promising findings across multiple studies, field-scale application still faces several challenges, including the selection of compatible strains, formulation stability of inoculants, and optimization of application techniques at the plantation scale. Future research should focus on strain-specific synergism, large-scale inoculant production, and integrated management strategies to translate laboratory findings into practical solutions for sustainable oil palm cultivation.
Uci Desyanti, M. H. Pratama, Anjelina Laura Bunda Sari et al.· ICEETE Conference Series· 0 citations
The role of PGPF in climate-resilient cropping systems and circular bioeconomy frameworks, including waste valorization and biofertilizer development is highlighted and key limitations such as host specificity, environmental variability, and scalability challenges are identified.
Kallol Das, A. Sarker, D. Deepo et al.· Phyton· 0 citations
Findings highlight the potential of Rhizobium inoculation to enhance crop resilience in salt-affected agroecosystems and demonstrate that symbiosis correlates with a more efficient and physiologically moderated acclimation to salinity in legumes.
María Isabel López-Román, L. Zurita, Cristina Castaño-Herrero et al.· Plant, Cell and Environment· 0 citations
Plant–microbe interaction is an essential component of sustainable agriculture which promotes plant growth, improves nutrient assimilation, and enhances plant resistance to various environmental stress conditions. Beneficial microbes, such as rhizobacteria, mycorrhizal fungi, and endophytes, boost plant functions using molecular signaling, phytohormone modification, systemic resistance induction, and pathogen antagonism. The use of new multi-omics techniques has uncovered complicated communication systems mediated by root exudates, recognition via receptors and microbial community functioning. In this review, the current understanding of the molecular basis of plant–microbe associations and their roles in combating drought, salinity, temperature, and heavy metals stresses is summarized. Special attention is paid to the promising approach based on microbiome engineering, synthetic communities and next generation biofertilizers for climate-smart agriculture. The main difficulties associated with environmental fluctuations, host specificity, inconsistency at field scale, and the lack of omics and bioinoculant validation guidelines are also highlighted.
Bishal Sarkar, Saumendu Deb Roy· Discover Plants· 0 citations
Evidence shows that stress mitigators can reduce MNPs-induced stress by improving rhizosphere microbial communities, increasing plant growth and photosynthetic efficiency, and regulating biochemical, transcriptomic, and metabolomic responses.
Wardah Azhar, Ali Raza Khan, Abdul Salam et al.· Journal of Agricultural and...· 0 citations
Most legumes form symbioses with both rhizobial bacteria and arbuscular mycorrhizal (AM) fungi, which supply nitrogen (N) and phosphorus (P) respectively. These two symbioses are established through a partly shared signalling pathway in the host root and are functionally linked through plant N:P balance. Because both partners draw on host photosynthate, the balance of benefits between them may shift under environmental stress, yet how warming and drought alter the mycorrhizal contribution to nodulation remains unclear. In a greenhouse experiment with alfalfa (Medicago sativa), we examined the effects of drought, warming, and AM fungi across eight combinations. After four months, we quantified root nodule biomass and number as primary nodulation metrics, and further measured plant nutrient content and nitrogenase activity to clarify whether changes in nodulation arose from functional impairment or translated into nutritional consequences for the host. Under control conditions, AM fungi increased root biomass allocation to nodules and fresh nodule biomass, and mycorrhizal colonization was positively associated with nodule biomass. Nodule biomass was negatively correlated with plant P concentration, consistent with nodulation imposing a substantial P cost. Under combined warming and drought, however, these positive effects on nodulation were no longer detected; instead, AM fungi increased shoot P concentration and content, an effect absent under control conditions. Together, these results suggest that compound climate stress redirects the mycorrhizal contribution away from supporting energy-intensive nodulation and towards maintaining host shoot P status. The beneficial interactions between rhizobia and AM fungi are essential for nutrient acquisition, but warming and drought can weaken these advantages. This emphasizes the urgent need for strategies that enhance legume-microbe partnerships amid climate variability for sustainable agriculture.
Xiao Dong, Xue Han, Yushan Bo et al.· Ecological Processes· 0 citations